1. Field of the Invention
This invention relates generally to devices for interventional therapeutic treatment or vascular surgery for treatment of defects in the vasculature, and more particularly concerns a system and method for delivering intravascular interventional devices, such as for treatment of aneurysms.
2. General Background and State of the Art
Vascular interventional devices such as vasoocclusive devices are typically placed within the vasculature of the human body by use of a catheter. Vascular interventional devices such as stents can be placed within an occluded vessel to facilitate blood flow through the vessel, and vasoocclusive devices are typically either placed within a blood vessel to block the flow of blood through a vessel making up that portion of the vasculature by the formation of an embolus, or are placed within an aneurysm stemming from the vessel to form such an embolus within the aneurysm. Vasoocclusive devices used for these procedures can have a wide variety of configurations, and aneurysms have been treated with external surgically placed clips, detachable vasoocclusive balloons and embolus generating vasoocclusive devices such as one or more vasoocclusive or embolic coils.
The delivery of such vasoocclusive devices has typically been accomplished by a variety of means, including via a catheter in which the device is pushed through an opening at the distal end of the catheter by an elongated flexible pusher member to deploy the device. The vasoocclusive devices can be produced in such a way that they will pass through the lumen of a catheter in a linear shape and take on a complex shape as originally formed after being deployed into the area of interest, such as in an aneurysm.
Detachable vasoocclusive devices are typically embolic coils fixed to a distal end of a flexible pusher member for delivery of the embolic coils, and may be detached mechanically, electrically or by some other means from the flexible pusher member at the target location. The detachable embolic coils can be delivered to the target location and detached if correctly sized and positioned, or the embolic coils may be withdrawn without being detached if the coils are not correctly sized, if the coils are not correctly positioned, or if the microcatheter positioning is lost. Some available vasoocclusive devices are not reused during a patient procedure if they are removed during the procedure, due to the inability to reload the device into the microcatheter. It is therefore desirable to provide a system and method for reusing vasoocclusive devices during a clinical procedure after removal from a microcatheter introducer.
One such system and method allowing the reuse of vasoocclusive devices after removal from a microcatheter introducer during a clinical procedure provides for an introducer sheath for a therapeutic vasoocclusive device which includes an assembly of a flexible pusher member and an embolic coil. The introducer sheath is formed from a hollow, elongated tubular member, and includes a longitudinal slot formed in the upper wall of the introducer sheath and extending the length, or majority of the length, of elongated tubular member. The slot permits introduction of the vasoocclusive device into the interior channel of the introducer sheath, and permits the introducer sheath to release the vasoocclusive device for introduction into a microcatheter, for deployment during a clinical procedure. The vasoocclusive device can be manually placed into the introducer sheath by an operator by using the finger and thumb of one hand to pinch the device positioning unit into the introducer sheath. Similarly, the vasoocclusive device can be manually released from the introducer sheath by pinching the introducer sheath to open the slot, and bending the introducer sheath to expose the distal tip of the vasoocclusive device, which can then be stripped out of the introducer sheath along the length of the slot. However, such manual techniques of sheathing and unsheathing a vasoocclusive device from the introducer sheath are highly dependent upon the manual dexterity of the operator. It would be desirable to improve the resheathing and unsheathing of a vasoocclusive device from such an introducer sheath by providing a tool that will aid in the unsheathing and resheathing of the vasoocclusive device in such an introducer sheath. The present invention satisfies these and other needs.